Prenatal prediction of spinal muscular atrophy by SMN deletion analysis.

The objective of this study was to provide prenatal prediction of spinal muscular atrophy (SMA) by survival motor neuron (SMN) gene deletion analysis and genetic counseling in families with previous child affected with SMA. The SMN gene is absent or interrupted in approximately 95% of SMA patients independence of clinical severity. We study four families with one previous child affected in each by performing the SMN deletion analysis in the index case. When a homozygous deletion in exon 7 or exon 8 is found, we offer prenatal prediction to the family. All four index cases had homozygous deletions of the SMN gene. Prenatal diagnosis by amniocentesis was performed in all pregnancies. Two pregnancies were positive for the homozygous deletion of the SMN gene, non-directive counseling was given and the two pregnancies were terminated. The other two pregnancies showed no deletion of the SMN gene. The unborn child is yet to be followed up. The prenatal prediction of SMA shows considerable requirements and potential effectiveness in prevention of the SMA in families at risk which cut the cost of care in this incurable disease.

Colchicine-induced myopathy in renal failure.

A 60 year-old woman with chronic renal failure developed acute proximal muscle weakness after receiving a regular dosage of colchicine. Elevation of muscle enzymes and electromyography were compatible with myopathy. Muscle biopsy revealed variation in muscle fiber size and few vacuolated fibers which were features of colchicine-induced myopathy. The clinical improvement and decreasing in muscle enzyme level occurred after colchicine withdrawal. Other potential causes of myopathy such as chronic renal failure and other drugs were ruled out. We suggested that colchicine should be used with caution in the presence of renal failure especially when other drugs which affect the metabolism of colchicine are also prescribed.

Diagnosis and carrier detection in a Duchenne muscular dystrophy family by multiplex polymerase chain reaction and microsatellite analysis.

We used multiplex PCR and a microsatellite or STR analysis for diagnosis and carrier detection in a DMD family. Two affected patients both demonstrated deletion of exon 51 by multiplex PCR. The microsatellite or STR analysis showed that the mother and all sisters except the eldest sister of the patients carried the disease allelle. Therefore, all of them except the eldest sister were carriers. We present the need to introduce the molecular techniques to improve a mode of diagnosis and management of DMD patients in the Thai community.

Multiplex PCR to detect the dystrophin gene deletion in Thai patients.

We have demonstrated the usefulness of the multiplex PCR to directly detect the dystrophin gene mutation. Prenatal diagnosis and confirmation of clinical diagnosis of DMD/BMD via non invasive technique are now possible. Nine DMD and one BMD patients were tested. Five DMD patients demonstrated deletion. Thus, this multiplex PCR could detect deletion in approximately 50 per cent of DMD/BMD Thai patients. Eighty per cent of the deletions were in the distal part, whereas, 20 per cent were in the proximal part. We are planning to establish other molecular techniques such as linkage analysis, cDNA hybridization and immunostaining of dystrophin protein to improve a mode of diagnosis and management of DMD/BMD patients in the Thai community.

Rapid Plasma Reagin test (RPR) compared to Venereal Diseases Research Laboratory test (VDRL) for the diagnosis of syphilis in pregnancy.

Obstetric departments which provide service for a large number of patients from different parts of the country and socioeconomic backgrounds like the Obstetric Department of Chulalongkorn hospital, need to develop rapid laboratory tests which can cope with the volume of work and yet provide sound laboratory data for management decisions. We, therefore, undertook a study of the suitable Rapid Plasma Reagin (RPR) test as a diagnostic tool for syphilis in 9,347 pregnant women who attended antenatal clinics at this institute from August 1984 to May 1985. The RPR test was used in addition to the routine serological tests for syphilis namely the VDRL, TPHA and/or FTA-ABS. Analysis of results confirmed that the RPR test fulfilled all laboratory results for clinical requirements. The results from RPR and VDRL were not significantly different. Their sensitivities were 90.86 and 89.95 per cent, their specificities were 99.57 and 99.68 per cent, their positive predictive values were 82.11 and 85.92 per cent, their negative predictive values were 99.8 and 99.78 per cent, and their accuracy was 99.39 and 99.47 per cent respectively. In our study it was found that the RPR test could provide a laboratory diagnosis in 60-90 minutes; in the same morning period when 15-20 prenatal patients were seen for the first time. The above results suggest that the RPR test is a rapid and reliable tool which is particularly suitable for syphilis screening in a busy antenatal clinic. The test enabled all 197 patients with syphilis in pregnancy to be treated promptly and without any loss of follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of sexual contacts of syphilitic pregnant women.

Between August 1984 and May 1985, 197 syphilitic pregnant women were diagnosed at the antenatal clinic, Department of Obstetrics & Gynaecology, Faculty of Medicine, Chulalongkorn University. One hundred and sixty-nine male sexual contacts were serologically tested for syphilis and seventy-eight cases were found positive. Twenty-eight cases refused to be tested. Thirty-two syphilitic male contacts had cerebrospinal fluid tests and four were found to be abnormal. Fifty-three cases or 67.9 per cent of 78 syphilitic male consorts did not complete a full diagnostic and treatment protocol. They preferred to be treated with benzathine penicillin G 2.4 million units intramuscularly for 3 consecutive weeks. After this treatment no patient agreed to a repeat spinal tap. This behavioral attitude concurred with their socioeconomic background. All were from a low socioeconomic group and lacked health knowledge. This made it difficult to work with them and contributed to inadequate management of their disease.

Effectiveness of benzathine penicillin regimen in the treatment of syphilis in pregnancy.

The intramuscular injection of benzathine penicillin G 2.4 million units weekly for 3 consecutive weeks to syphilitic pregnant women was again confirmed to be clinically effective for prevention of their neonates from congenital syphilis and well accepted as treatment for syphilis in pregnancy. It was administered to 184 cases, or 93.5 per cent, of 197 syphilitic gravidas. It was found that pregnancy outcomes in terms of abortion, stillbirth, prematurity, full term delivery, neonatal birth weight, macroscopic examination of the placenta and general physical examination of the neonate were clinically useful as a parameter to evaluate the effectiveness of the therapy for the infant. Clinical symptoms and signs in the mother, serological tests for syphilis in the gravida and cord blood of the newborn, and placental weight were not useful in the evaluation of adequacy of treatment of our study group.